You can create the button on a page and with right click move it or copy it to the Master Page. Just make sure that the address of the button is available on the master page.
Also you can create the switch button on the Master Page.

Make sure that the name of your audio file is in the button and in the Folder Multimedia Data. Ex mp3#music , has to have a file mp3 called music on the Multimedia Data File. You can also create mp3#stop and mp3#pause.

When you install the Sunlite, there is a demo page called Traditional Lighting, there you can see the comands.